1. Field of the Invention
This invention relates to biopsy devices and, more specifically, to devices that encapsulate a tissue specimen.
2. Description of the Related Art
The prior art discloses numerous methods for surgically removing an internal tissue specimen from a target body. Techniques and the requisite medical devices exist to remove tissue specimens of all sizes. A basic technique is to make an incision proximate to the area of the tissue specimen and excise it with a scalpel. This technique can be extremely invasive, result in trauma to proximate tissue and a maximum amount of scar tissue, and leads to additional healthy tissue being removed unnecessarily.
The prior art also discloses techniques and methods that are less invasive than excising the tissue sample with a scalpel. As disclosed in U.S. Pat. No. 5,788,709, a trocar is inserted into the target body, the target body is insufflated and the tissue specimen is severed. The tissue specimen may be a cyst, a tumor, parts of an organ, a whole organ, a diseased portion of the body, a biopsy sample, or any other specimen that is desired to be removed.
The prior art further discloses many techniques for removing the tissue specimen. Proper removal of the tissue specimen is critical. Cysts and other types of diseased tissue may spill into the surrounding tissue, resulting in inflammation and transfer of malignant cells or disease. Tumors or organs larger than the trocar need to be segmented for removal, which also may lead to inflammation and transfer of malignant cells. The segmenting of the tumors or organs is technically complicated and very time consuming. In certain methods, such as motor driven morcellators, there is a high danger of injury for the organs and blood vessels in the body. Further, morcellators render the tissue specimen unusable for certain pathologies.
Devices and techniques for removing the tissue specimen while limiting the transfer of malignant or diseased cells are also disclosed in the prior art. U.S. Pat. No. 5,037,379 discloses a surgical tissue bag for percutaneously debulking tissue. The debulking is performed by inserting the bag through an access sheath into a body cavity, inserting a surgically removed tissue mass through an open end of the bag, closing the end of the bag and pulling the closed end of the bag out of the body cavity. The end of the bag is then opened and morcellating or debulking of the tissue through the open end of the bag is performed while the remainder of the bag remains in the body cavity. The bag is made of flexible and foldable material and includes an inner layer of puncture resistant material such as nylon in either woven or solid layer form for resisting penetration by a surgical morcellating instrument. The outer layer of the bag is made of a moisture proof polymeric material.
U.S. Pat. No. 5,215,521 discloses an entrapment envelope having a means for opening and closing. The entrapment envelope is constructed of flexible, low fluid permeability materials having sufficient strength to contain morcellator entry, organ fragmentation and removal.
U.S. Pat. No. 5,337,754 discloses a tissue isolation bag which expands from a collapsed configuration to an expanded configuration when pressurized gas or liquid is supplied thereto.
U.S. Pat. No. 5,330,483 discloses a tissue reduction device which is thermally activated and is used in conjunction with a tissue isolation bag. The tissue reduction member is in an expanded condition at body temperature but shrinks to a smaller specimen reduced configuration when heated to a temperature above body temperature.
U.S. Pat. No. 5,611,803 discloses a tissue segmentation device incorporated into an isolation bag for segmenting tissue during an operation such as in laparoscopic surgery. The device includes one or more loops of high strength wire which can be mechanically reduced in loop diameter to cut tissue into smaller pieces. The wire loops can be heated electrically to aid in the cutting through hard-to-cut parts of the tissue. The wire can be of a shape memory alloy which shrinks when heated to form a smaller diameter loop.
U.S. Pat. No. 5,788,709 discloses a tissue specimen being removed with a bag having a side opening and an end opening. The bag is inserted into the abdominal cavity with the end opening of the bag remaining extracorporeal to a thread casing that extends through the abdominal wall. The tissue specimen is directed through the side opening and into the bag. The bag is reduced in size to snugly hold the tissue specimen. The tissue specimen is then segmented. The bag has positioning pins to hold the tissue specimen in place in the bag during the segmenting process. The segmented tissue specimen is removed through the end opening.
The bags disclosed in the prior art for retaining the tissue specimen and performing various procedures on the specimen have the disadvantage of requiring a relatively large sized insufflated region to perform the encapsulation.
U.S. Pat. No. 5,417,697 discloses a polyp removal device that severs and removes the polyp. The snare is an electrically conductive cauterization loop that is ejected from the end of an endoscopic assembly. A cup-shaped web member is also ejected from the endoscopic assembly end. The loop is placed over the polyp and the web member is opened up. A vacuum is applied to the web member to secure the polyp in the cup-shaped web member. Electrical current is conducted to the loop to sever the polyp from the patient, and the loop is closed. The severed polyp is held in the web member by suction and is removed from the patient. This device has the restriction of being used with polyps. Additionally, the entire polyp is not enclosed, resulting in possible contamination of tissue during the removal procedure.
U.S. Pat. No. 5,643,282 discloses a surgical instrument to remove excised tissue from an insufflated anatomic cavity through a body wall overlaying an endoscopic work space. A tissue grasping instrument attaches itself to the excised tissue and the tissue is pulled through a sleeve, or snake, which extends through the body wall. This device has numerous disadvantages, including the restriction of grasping the tissue specimen, which may result in severing portions of the tissue specimen which in turn remain in the patient to cause inflammation, spreading of disease, and contamination by malignant cells.
Further, the cited prior art does not disclose devices or techniques suitable for removing a cyst or a tumor from a region that is not insufflated while minimizing deposition of cells therefrom into the patient, such as removing a tumor from a breast.